Ford F150 Pickup. Manual - part 1000

Fig. 23: Removing Water Thermostat - 4.2L 
Courtesy of FORD MOTOR CO. 

Installation 

NOTE:

The water thermostat is indexed and must be installed correctly.

 

2003 Ford Pickup F150 

2003 ENGINE Engine Cooling - F150 Pickup

  

Fig. 24: Installing Thermostat - 4.2L 
Courtesy of FORD MOTOR CO. 

1. Install the water thermostat. 

z

Install the thermostat.  

z

Install the water outlet adapter and the bolts.  

2. Connect the upper radiator hose.  

3. Fill the cooling system. For additional information, refer to COOLING SYSTEM DRAINING, 

FILLING & BLEEDING .  

THERMOSTAT - 4.6L & 5.4L 

Removal 

1. Partially drain the cooling system. For additional information, refer to COOLING SYSTEM 

DRAINING, FILLING & BLEEDING .  

2. Disconnect the upper radiator hose.  

3. Remove the water outlet connection. 

1. Remove the bolts.  

2. Remove the water outlet connection. 

 

2003 Ford Pickup F150 

2003 ENGINE Engine Cooling - F150 Pickup

  

Fig. 25: Removing Water Outlet Connection - 4.6L & 5.4L 
Courtesy of FORD MOTOR CO. 

4. Remove the (A) water thermostat (8575) and the (B) O-ring seal. 

z

Discard the (B) O-ring seal.  

 

2003 Ford Pickup F150 

2003 ENGINE Engine Cooling - F150 Pickup

  

Fig. 26: Removing Water Thermostat & O-Ring Seal - 4.6L & 5.4L 
Courtesy of FORD MOTOR CO. 

Installation 

1. Use a new (A) O-ring seal to position the (B) water thermostat in the (C) upper intake manifold (9424). 

 

2003 Ford Pickup F150 

2003 ENGINE Engine Cooling - F150 Pickup